KeSetTargetProcessorDpc function (ntddk.h)

The KeSetTargetProcessorDpc routine specifies the processor that a DPC routine will be run on.


void KeSetTargetProcessorDpc(
  CCHAR  Number



[in, out] Pointer to the caller's DPC object, which KeInitializeDpc already initialized.


[in] Specifies the zero-based number of the target processor on which the DPC should be queued and executed.

Return value



On multiprocessor systems, each processor has its own DPC queue. The KeSetTargetProcessorDpc routine specifies which processor's queue the system should use when the driver calls KeInsertQueueDpc or IoRequestDpc to queue a DPC to be run later.

Starting with Windows Vista, you can also use KeSetTargetProcessorDpc to specify the target processor for threaded DPCs.

A call to KeSetTargetProcessorDpc that occurs after a DPC object has been queued has no effect on the selection of a processor for the DPC routine to run on. To control the selection of the target processor, a KeSetTargetProcessorDpc call must occur before the call to KeInsertQueueDpc or IoRequestDpc that queues the DPC object.

For more information about DPC queues, see Organization of DPC Queues.

Windows 7 and later versions of Windows support processor groups. Drivers that are designed to handle information about processor groups should use the KeSetTargetProcessorDpcEx routine, which specifies a processor group, instead of KeSetTargetProcessorDpc, which does not. However, the implementation of KeSetTargetProcessorDpc in Windows 7 and later versions of Windows provides compatibility for drivers that were written for earlier versions of Windows, which do not support processor groups. In this implementation, if Number is less than the number of active logical processors in group 0, KeSetTargetProcessorDpc sets the target for the DPC to the processor in group 0 that is specified by Number. Otherwise, the DPC target does not change.


Minimum supported client Available starting with Windows 2000.
Target Platform Universal
Header ntddk.h (include Wdm.h, Ntddk.h, Ntifs.h)
Library NtosKrnl.lib
DLL NtosKrnl.exe
IRQL Any level

See also